For the usage and dosage of concentrated sodium chloride, it needs to be specifically analyzed according to the patient’s serum Na+ count. low Na+ is divided into mild, moderate and severe, for mild hyponatremia, when the serum sodium is around 130 mmol/L, oral sodium supplementation can be taken, 3 times a day, 1-3 concentrated sodium chloride injections can be taken at a time, and the total intake of no more than 9g a day, which can usually correct the mild hyponatremia. If the hyponatremia is moderate, with serum sodium usually at 120-130 mmol/L, it is necessary to give concentrated sodium chloride injection intravenously, which should cause the blood sodium to rise at a rate of 0.5 mmol/L per hour, usually with 0.9% sodium chloride injection with 3.0 g of concentrated sodium chloride, and a drip rate of 1.5 mmol/L per hour is sufficient. In case of severe sodium deficiency, which refers to serum sodium below 120 mmol/L or the appearance of obvious central nervous system symptoms, it is required to raise the Na+ concentration to 120 mmol/L within 6 hours, and the formula for sodium supplementation needs to be applied. The formula for sodium supplementation is the actual amount of sodium supplementation equals 142 minus the blood sodium concentration of Na+, multiplied by body weight, and multiplied by 0.2 is sufficient.